1. Field of the Invention
The field of the invention pertains to for devices having patterned nanofeatures suitable for controlled cell culture and for microanalysis of protein patterns deposited thereon.
2. Background Art
Controlled cell culture and analysis of proteins on a nano scale has been achieved in the past by patterning of substrates with adherent domains suitable for receiving adherent proteins and other molecules such as DNA, RNA, etc. Prior methods have involved patterning processes typical for the production of integrated circuits and like products. However, the patterning process is relatively expensive, limited to relatively flat surfaces, and the patterns created are limited with respect to their size and spacing, and further limited in size by availability and cost of large size substrates.
For example, S. Boateng et al., “Peptides Bound to Silicone Membranes and 3D Microfabrication for Cardiac Cell Culture,” ADV. MATER., 2002, 14, No. 6, pp. 461–463 discloses the use of patterned silicone elastomer substrates in in vitro cardiac mechano-biological studies. The patterned substrates are created by photolithography and consist of parallel grooves of 10 μm width and 10 μm spacing. E. Ostuni et al., “Patterning Mammalian Cells Using Elastomeric Membranes,” LANGMUIR 2000, 16 pp. 7811–7819 discloses freestanding lift-off membranes having a pattern of holes, which are applied to a substrate, the substrate is treated chemically and/or biologically through the holes, and the membrane is then peeled from the substrate. The holes are on the order of 50–80 μm in size.
S. Zankovych et al., “Nanoimprint Lithography: Challenges and Prospects,” NANOTECHNOLOGY 12 (2001), pp. 91–95 discloses pressure imprinting utilizing a metal-plated die master which is then pressed into a polymer above its glass transition temperature. The polymer is first cast onto silicon. Die lifetime is a problem, and the size and spacing of nanofeatures becomes increasingly problematic as size and spacing decrease below about 100 nm.
S. Sun et al., “Nanoscale Molecular Patterns Fabricated by Using Scanning Near-Field Optical Lithography,” J. AM. CHEM. SOC., Vol. 124, 11, pp. 2414–2415 discloses patterning of gold surfaces treated to be covered with self-assembled monolayers by adsorption of alkanethiols, followed by programmed irradiation employing a U.V. laser source and a scanning near-field optical microscope. Line widths of 40 nm were routinely achieved. While small device features are achievable, the method is time-consuming and limited with respect to substrate.
K. Lee, et al., “Protein Nanoarrays Generated by Dip-Pen Nanolithography,” SCIENCE, V. 295, pp. 1702–1705, discloses patterning of gold plated substrates by depositing dots or grids of 16-mercaptohexadecanoic acid onto the substrate, followed by passivation of surrounding areas with 11-mercaptoundecyl-tri(ethylene glycol). Proteins could be absorbed on the active areas by immersion into an aqueous solution of protein. This process is limited in scope due to the necessity of employing gold plated substrates, and requires complex control of the deposition apparatus.
It would be desirable to provide a method for nanopatterning which can be applied to substrates of large surface area, on planar, non-planar, or even three-dimensional surfaces, which does not rely on typical patterning methods for its production, and which can be effected at reasonable cost.